A study on the fatigue characteristics of SLS 3D printed PA2200 according to uniaxial cyclic tensile loading

SLS 3D 프린터를 이용하여 제작된 PA2200의 단축 반복 인장하중에 따른 피로 특성에 관한 연구

  • Park, Jun-Soo (Dept. of Mechanical Design and Manufacturing Engineering, Seoul National University of Science and Technology) ;
  • Jeong, Eui-Chul (Molds & Dies Technology R&BD Group, Korea Institute of Industrial Technology) ;
  • Choi, Han-Sol (Molds & Dies Technology R&BD Group, Korea Institute of Industrial Technology) ;
  • Kim, Mi-Ae (Molds & Dies Technology R&BD Group, Korea Institute of Industrial Technology) ;
  • Yun, Eon-Gyeong (Molds & Dies Technology R&BD Group, Korea Institute of Industrial Technology) ;
  • Kim, Yong-Dae (Molds & Dies Technology R&BD Group, Korea Institute of Industrial Technology) ;
  • Won, Si-Tae (Dept. of Mechanical Design and Manufacturing Engineering, Seoul National University of Science and Technology) ;
  • Lee, Sung-Hee (Molds & Dies Technology R&BD Group, Korea Institute of Industrial Technology)
  • 박준수 (서울과학기술대학교 기계디자인금형공학과) ;
  • 정의철 (한국생산기술연구원 금형기술그룹) ;
  • 최한솔 (한국생산기술연구원 금형기술그룹) ;
  • 김미애 (한국생산기술연구원 금형기술그룹) ;
  • 윤언경 (한국생산기술연구원 금형기술그룹) ;
  • 김용대 (한국생산기술연구원 금형기술그룹) ;
  • 원시태 (서울과학기술대학교 기계디자인금형공학과) ;
  • 이성희 (한국생산기술연구원 금형기술그룹)
  • Received : 2020.03.18
  • Accepted : 2020.03.31
  • Published : 2020.03.31

Abstract

In this study, the fatigue behavior and fatigue life characteristics of PA2200 specimens fabricated by SLS 3D printer were studied. Fatigue tests were performed according to the standard specification (ASTM E468) and fatigue life curves were obtained. In order to perform the fatigue test, mechanical properties were measured according to the test speed of the simple tensile test, and the self-heating temperature of the specimen according to the test speed was measured using an infrared temperature measuring camera in consideration of heat generation due to plastic deformation. There was no significant difference within the set test speed range and the average self-heating temperature was measured at 38.5 ℃. The mechanical strength at the measured temperature showed a relatively small difference from the mechanical strength at room temperature. Fatigue test conditions were established through the preceding experiments, and the loading conditions below the tensile strength at room temperature 23 ℃ were set as the cyclic load. The maximum number of replicates was less than 100,000 cycles, and the fracture behavior of the specimens with the repeated loads showed the characteristics of Racheting. It was confirmed that SLS 3D printing PA2200 material could be applied to the Basquin's S-N diagram for the fatigue life curve of metal materials. SEM images of the fracture surface was obtained to analyze the relationship between the characteristics of the fracture surface and the number of repetitions until failure. Brittle fracture, crazing fracture, grain melting, and porous fracture surface were observed. It was shown that the larger the area of crazing damage, the longer the number of repetitions until fracture.

Keywords

Acknowledgement

Supported by : 중소벤처기업부

본 연구는 중소벤처기업부 중소기업상용화기술개발 세부사업의 구매조건부 신제품개발 사업(S2652287(SE19640))에 의해 수행되었으며, 이에 관계자 여러분께 감사드립니다.

References

  1. Wohlers, T. and Gornet, T., "History of additive manufacturing", Wohlers Report : Additive Manufacturing and 3D Printing State of the Industry Annual Worldwide Progress Report, 2011.
  2. Goodridge, R. D., Tuck, C. J and Hague, R. J. M., "Laser sintering of polyamides and other polymers", Progress in materials science, Vol. 57, pp. 229-267, 2012. https://doi.org/10.1016/j.pmatsci.2011.04.001
  3. L. Lu, J. Fuh, "Laser-induced Materials and Processes for Rapid Prototyping", Kluwer, London, 2001.
  4. B. V. Hooreweder, D. Moens, R. Boonen, J. P. Kruth, P. Sas, "On the difference in material structure and fatigue properties of nylon specimens produced by injection molding and selective laser sintering", Polymer Testing 32, pp. 972-981, 2013. https://doi.org/10.1016/j.polymertesting.2013.04.014
  5. V. E. Rubtsov, A. V. Kolubaev, "Effect of Heat Generation Due to Plastic Deformation on Behavior of Surface-Layer Material during Sliding", Journal of Friction and Wear, Vol. 30, pp. 324-328, 2009. https://doi.org/10.3103/S1068366609050043
  6. Y. L. Lee, Pan, J., Hathaway, R. and Barkey, M., "Fatigue Testing and Analysis: Theory and Practice", Elsevier, Boston, p. 106, 2005.
  7. Behzad, G., Hamid, N, Michele, R., "Dynamic simulation of a flexible pavement layers considering shakedown effects and soil-asphalt interaction", Trnasportation Geotechnics, Vol. 7, pp. 40-58, 2016. https://doi.org/10.1016/j.trgeo.2016.04.003
  8. A. J. Kinloch, R. J. Yong,. "Fracture Behaviour of Polymers", Applied Science, London, pp. 147-181, 1978.
  9. B. V. Hooreweder, F. D. Coninck, D. Moens, R. Boonen, P. Sas, "Microstructural characterization of SLS-PA12 specimens under dynamic tension/compression excitation", Polymer Testing, Vol. 30, pp. 611-615, 2009. https://doi.org/10.1016/j.polymertesting.2011.04.007
  10. T. Jollivet, A. Darfeuille, B. Venquin, S. Pillot, "Rapid Manufacturing of Polymer Parts by Selective Laser Sintering", International Journal of Material Forming, Vol. 12, pp. 697-700, 2009.
  11. Bannantine, Julie. A., Comer, Jess. J., Handrock, J. L., "FUNDAMENTALS OF METAL FATIGUE ANALYSIS", Englewood Cliff, New Jersey 07632, pp. 4-255, 1990.